Vehicle suspension apparatus

ABSTRACT

A trailing arm suspension unit for use on a vehicle including a ring bearing, a trailing arm, a spring and damper for providing large vertical wheel travel in a jounce and rebound suspension condition. The ring bearing may include external threads for rotationally connecting the trailing arm to a mounting plate or a hull of the vehicle. Further, supply lines for electrical and fluids may be passed through the opening in the ring bearings without the use of a slip ring and passed through a passage in the trailing arm to a wheel on the vehicle. The spring and damper may be located on top of the trailing arm and separately connected to the mounting plate to generate significant mechanical advantage. The geometry of the spring, damper, and trailing arm allow the spring in the suspension unit to be gas cylinder employing air.

CROSS REFERENCE TO RELATED APPLICATIONS

This application takes priority from U.S. non-provisional applicationSer. No. 60/470,436 filed May 15, 2003, which provisional application isherein incorporated by reference.

BACKGROUND OF THE RELATED ART

This invention relates generally to vehicle suspension systems, and moreparticularly to an external trailing arm pneumatic suspension withintegral accommodations for electric or gear driven wheel ends.

Conventional trailing arm suspension devices are known and used invehicles designed for rugged terrain and severe conditions. For example,trailing arm suspensions have long been used on tanks, providing longvertical travel suspension for use under military conditions. A singleunit of a trailing arm suspension system typically includes a mountingplate connecting a swing arm to a hull of a vehicle and a hub or wheelspindle at the end of the swing arm for connecting a wheel to thesuspension system. Shocks and springs act on the swing arm to controlthe characteristics of the suspension system and are located within theswing arm or trailing arm, resulting in poor mechanical advantage.Further, gas springs, operated with nitrogen, are often used in thesuspension units. Unfortunately, a notable logistics burden results fromthe use of nitrogen when the vehicle is far from home or a ready sourceof pressurized nitrogen.

Traditional trailing arm suspension systems are also bulky and requiresignificant space to accommodate the structure requirements of thetrailing arm suspension. The mounting plates of traditional trailing armsuspensions require precious needed space between the wheel and the hullof the vehicle to connect large bearing flanges on hollow or ringbearings. The mounting plates are also expensive to employ because ofthe need to manufacture separate plates for different positions and ondifferent sides of the hull of the vehicle. Further, electrical,pneumatic, and/or mechanical gears and shafts require routing andspecial considerations to avoid conflicts with the mounting plates andexposure to rocks, debris, and ordinance under operating conditions.

Traditional trailing arm suspension systems also lack efficientconnection systems for electrical, coolant, and mechanical connectionsthat are protected between the hull and the wheel and do not leakfluids. For electrical drive applications, traditional systems do notprovide direct plug-in connectors for cables while allowing flexingduring arm rotation and vertical wheel movement.

Therefore, what is needed is a trailing arm suspension system includinga geometry capable of maximizing mechanical advantage of the spring anddamper forces, a reduced and efficient connection from the trailing armto the bearing to the mounting plate, and an efficient and reliableconnection of mechanical or electrical power between the hull of avehicle and a wheel.

SUMMARY OF THE INVENTION

In a first aspect, the present invention includes a trailing armsuspension system interfaced between a hull of a vehicle and a wheel ofthe vehicle. The suspension system includes a trailing arm elementhaving a first end and a second end and a passage therein. The trailingarm element also includes a wheel mount positioned between the first endand the second end of the trailing arm element and connected to thepassage of the trailing arm element. The suspension system also includesa spring element and a damper element. The spring element includes afirst end and a second end wherein the second end of the spring elementis attached to the second end of the trailing arm and the damper elementincludes a first end and a second end wherein the second end of thedamper element is attached to the second end of the trailing arm. Thespring element and the damper element are positioned external to andabove the trailing arm element.

In an embodiment of the present invention, the suspension system furtherincludes a ring bearing and a mounting plate wherein the trailing armelement and the mounting plate are rotationally connected by the ringbearing. The ring bearing may also include a first set of externalthreads which are structured and arranged to secure the bearing to thetrailing arm element. The ring bearing may include a second set ofexternal threads which are structured and arranged to secure the ringbearing to the mounting plate.

In yet another embodiment, the mounting plate is symmetrical about atleast one axis.

In still another embodiment of the present invention, a plurality ofsupply lines may pass through the ring bearing and the passage of thetrailing arm element. The suspension system may also include a wheelassembly mounted to the wheel mount and a plurality of connectorsconnecting the plurality of supply lines to the wheel assembly. Aspindle may also be included on the wheel mount and the plurality ofconnectors may be structured and arranged about the spindle. Thesuspension system may include in the wheel assembly an electric drivemotor.

In another embodiment, the ring bearing and the wheel mount may beconnected by a mechanical transmission passing through the ring bearingand the passage of the trailing arm element.

In still another embodiment, the suspension system may include a gaspiston cylinder as the spring element. The gas piston cylinder mayinclude a dual-acting air cylinder with air independently supplied toboth sides of the gas cylinder piston. Further, the damper element maybe positioned above and substantially parallel to the spring element.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the present invention, it is believed the samewill be better understood from the following description taken inconjunction with the accompanying drawings, which illustrate, in anon-limiting fashion, the best mode presently contemplated for carryingout the present invention, and in which like reference numeralsdesignate like parts throughout the figures, wherein:

FIG. 1 is a schematic of the suspension system according to one aspectof the invention;

FIG. 2 is a perspective view of the suspension system according to oneaspect of the invention;

FIG. 3 is a side view with a partial cut-away of the suspension system,and in particular the spring and damper of the suspension system shownin FIG. 2;

FIG. 4 is a cross-sectional view of the multi-port assembly androtatable connection for the spring and damper according to one aspectof the invention;

FIG. 5 is a graph comparing the spring performance traits of singleacting air springs and dual acting air springs according to one aspectof the invention with the spring performance traits of linear springs;

FIG. 6 is a perspective view of a bearing of the suspension systemaccording to one aspect of the invention;

FIG. 7 is a side view of the suspension system of FIG. 2 in threepositions of movement relative to a static position;

FIG. 8 is perspective view of the suspension system of FIG. 2 withelements of the suspension transparently shown;

FIG. 9 is a bottom view with a partial cut-away of the suspensionsystem, and in particular the mounting plate, bearing and trailing armof the suspension system shown in FIG. 2;

FIG. 10 is a cross-sectional view through the bearing and the multi-portassembly of the suspension system according to one aspect of theinvention; and

FIG. 11 is an exploded view of the suspension system as shown in FIG. 2.

DETAILED DESCRIPTION

For simplicity and illustrative purposes, the principles of the presentinvention are described by referring mainly to the exemplary embodimentthereof. However, one of ordinary skill in the art would readilyrecognize that the same principles are equally applicable to, and can beimplemented in, many types of systems involving trailing arm suspensionsor other similar devices, and that any such variations do not departfrom the true spirit and scope of the present invention. Moreover, inthe following detailed description, references are made to theaccompanying figures, which illustrate specific embodiments. Electrical,mechanical, logical and structural changes may be made to theembodiments without departing from the spirit and scope of the presentinvention. The following detailed description is, therefore, not to betaken in a limiting sense and the scope of the present invention isdefined by the appended claims.

An embodiment of the invention generally relates to a structure orapparatus for the deployment of a trailing arm suspension system. Inembodiments of the invention, the suspension system may comprise aplurality of trailing arm suspension units. The number of units dependson performance requirements and/or configuration constraints, of thesystem or the vehicle in which the suspension system is deployed.

In one embodiment of the present invention, the suspension systemincludes a plurality of trailing arm units mounted on a vehicle. Eachunit may include a mounting plate, a trailing arm, wheel spindle, and aspring and damper. Embodiments of the invention may also include fullsymmetry of the mount plate such that the plate may be mounted on eitherside of a vehicle. The trailing arm may be rotatably attached to themounting plate using a hollow bearing. Also, the damper and shock may berotatably attached to the mounting plate. The connections of thetrailing arm to the mounting plate and the damper and spring to themounting plate may be spaced such that the suspension geometry creates asubstantial mechanical advantage for the spring and damper. Between theconnection of the trailing arm and the mounting plate and the connectionof the trailing arm and the damper and spring, a hub or wheel spindlemay be positioned for attachment of an electric drive motor ormechanical gears for driving a wheel or other device.

The units of the suspension system may also include the use of an airspring. The arrangement of the damper may include a “piggy-back” or“top” configuration/position over the air spring, providing easy accessand maintenance capability for replacing or fixing the spring anddamper. It is contemplated that the damper may be a typical automotivehydraulic damper. The damper may also be replaced with an activelycontrolled actuator. Although the spring may preferably use air as itsworking medium, other fluids and gases may be used in the spring of thesuspension units without deviating from the present invention.

It should be noted that the adoption of air gas in the spring or gascylinder in place of traditional nitrogen may eliminate the logisticsburden of providing high pressure nitrogen in rugged terrain or underdifficult circumstances. Air may be supplied by currently well known airdelivery systems to each of the suspension units on the vehicle and theair pressure may be automatically controlled to adjust thecharacteristics of the suspension. The use of air may also make theintroduction of cost effective gas seals possible and practical,allowing the adoption of an air-operated height/attitude managementsystem that avoids reliance on more expensive and fallible seals, oftenrequired with the use of other gases. The spring or gas cylinder mayalso employ a dual-acting air cylinder approach with air independentlysupplied to both sides of the gas cylinder piston, allowing optimizationof jounce and rebound spring characteristics. Although air in a dualacting suspension spring is contemplated as the preferred configurationfor the spring of the suspension unit, nitrogen may be used or othersuitable gas for the dual acting or single acting springs withoutdeviating from the true scope and spirit of the present invention.

An embodiment of the present invention may also include a hollowtrailing arm and a hollow bearing connecting the trailing arm to themounting plate. This hollow feature of the bearing and trailing arm mayallow the trailing arm suspension unit to accommodate an electricaldrive system or a mechanical drive system. The hollow characteristic mayalso allow important “feed” lines such as electrical and coolant linesto pass through the hollow bearing and through the hollow trailing armwithout the use of slip rings or other such devices. The hub or wheelspindle may also include the use of self-sealing electrical and coolantconnections to an electrical motor, mounted on the hub and located inthe hub of a wheel.

In one embodiment of the present invention, it is contemplated that thesuspension unit may rotate approximately 80 degrees, providing about 18inches of vertical travel relative to the ground. Typical settings forcross-country operation have the unit positioned to provide about 13inches of travel in the jounce condition and about 5 inches of travel inthe rebound condition. The suspension may be adjusted to differentheights by controlling the pressure in the spring of the suspension unitto raise and lower the suspension unit over the about 18 inches oftravel. This travel may allow the vehicle to set a wide range of bottomclearance heights for a vehicle and, at all but the extreme ends of thesuspension travel, the suspension unit may continue to provide springand damper performance.

Further, the suspension unit's geometry may generate significantmechanical advantage due to the positioning of the spring and the damperabove the trailing arm. This positioning may allow the efficient use ofair in lieu of other gases or fluids, while permitting high wheel travelin both the jounce and rebound conditions. This mechanical advantage mayalso permit static air pressure of the spring to be about 1000 psi,whereas traditional designs are usually closer to 2000 psi. This lowerstatic pressure reduces the maximum pressure experienced at full jounceto about 4000 psi whereas traditional designs are usually closer to8,000–10,000 psi, a challenging pressure for seals and sealing.

It is also contemplated that an embodiment of the present invention mayinclude jounce and rebound stops (with nonmetallic pads) integrated intothe mounting plate and suspension arm to prevent the suspension springand damper from being overly extended or compressed. A compressiblesleeve on the air actuator shaft may also snub the final inch ofactuator shaft translation, further protecting the suspension unitagainst over-travel.

The mounting plate, trailing arm, and other structures of the trailingarm suspension each may be implemented using, but not limited to,titanium, aluminum, invar, graphite epoxy, plastic, composites, siliconcarbide, shape memory materials, rigidizable materials and other similarmaterials. Individual components of the assembly need not all be madefrom the same material. The trailing arm may have a design of a tube,box, truss, enclosed I-beam, isogrid, inflatable rigidizable, shapememory design or other similar design. The rotatable connections mayalso include actively controlled actuators, e.g., motors that may beactuated or passive, non-actuated joints.

It should be noted that the trailing arm suspension unit may also beemployed on a vehicle in a leading arm configuration. In such aconfiguration, the suspension arm may be directed toward the front ofthe vehicle without deviating from the scope and spirit of the presentinvention.

Referring now to FIG. 1, there is shown a schematic of the suspensionsystem according to one aspect of the invention. A wheel drive unit orwheel assembly 10 is shown connected to an e-drive brake interface 20 byconnection lines of air 12, data 14, power 15, brake 17 and coolant 19.The e-drive 20 and the wheel drive 10 may be connected to the hull 40 ofa vehicle by the suspension system and particularly a unit of thetrailing arm suspension system 30.

The characteristics of the suspension system 30 may be at leastpartially controlled by the gas supply vehicle control system 50, whichcontrols the amount of air 12 supplied to the spring and damper. Thesuspension position 60 may report the position of the wheel from one ormore suspension units to the gas supply vehicle control system or heightcontrol system 50 to be used in controlling the amount of air deliveredfrom the air supply 70 to the suspension system 30. The power 15, brake17 and coolant 19 lines may be controlled by conventional onboardsystems (not shown).

In FIG. 2, a perspective view of the suspension system according to oneaspect of the invention is shown. A suspension unit 30 may include thetrailing arm or road arm 100 attached to a mounting plate 110. Thetrailing arm 100 may include a rotatable connection 120 for securing thetrailing arm 100 to the mounting plate 110. Mounting plate 110 may besymmetrical for use on either side of a vehicle. The mounting plate 110may be secured to the hull of a vehicle using the fasteners 111.

The trailing arm 100 also includes a hub or wheel mount 130 and a wheelspindle 140. Beyond the wheel mount 130, the trailing arm 100 includes amount 180 for attaching the spring 150 and the damper 160. The spring150 and the damper 160 is attached to the trailing arm 100 using themounting bracket 181 and also be attached to the mounting plate 110 andthe rotatable connection 170 using the mounting bracket 173. The spring150 and the damper 160 may also be directly connected to the trailingarm 100 and the mounting plate 110.

The spring 150 may be an external gas piston cylinder and the damper 160may be a piggy-backed damper cylinder pinned to the trailing arm 100 andthe mounting plate 110. The damper 160 may be a passive damper or anactive damper as desired or necessary for a particular application. Theconfiguration shown in FIG. 2 may provide over 18 inches of verticalwheel travel and provide easy access and replacement ability of thespring 150 and the damper 160.

Referring to FIG. 3, a partial cut-away view of the spring and damper ofthe suspension system according to one aspect of the invention is shown.The spring 150 may have an actuator pressure 151 and a back pressure 152on either side of a cylinder 153. The cylinder 153 may be connected to apiston 154 that connects to the rotatable connection 170. The rotatableconnection 170 may include a multi-port assembly for directing air intothe actuator pressure 151 and the back pressure 152. The damper 160 isalso shown in FIG. 3 and includes a cylinder 161 and a piston 162. Thepiston 162 may be connected to the rotatable connection 170 along withthe spring 150. The damper 160 also includes a working fluid 163.Although it is contemplated that the damper 160 may be a typicalautomotive shock, the damper 160 may include other dampers and workingfluids without deviating from the scope and spirit of the presentinvention.

It should be noted that the geometry of the connections 120 and 170 andthe attachment of the spring 150 and the damper 160 at the mount 180allow the spring 150 and the damper 160 to generate significantmechanical advantage for exerting forces from the spring 150 and thedamper 160. This mechanical advantage provides not only for the largevertical wheel travel of the suspension unit 30, as shown in FIG. 7, butalso provides the capability of using air in the spring 150 instead ofother working gases or fluids. An additional volume 155 is shown in FIG.3 and may be used to provide additional volume to the actuator pressure151 to improve or adjust the performance of the spring 150.

In FIG. 4, the rotatable connection or multi-port assembly 170 is shown.The connection 170 may supply air to the spring 150 when an air springis employed on the suspension system. Air may be fed from the gas supplyvehicle control system 50 and the air supply 70 into the actuatorpressure 151 and the back pressure 152. The connection 170 may alsoallow pressure to be exhausted from the actuator pressure 151 or theback pressure 152 in order to adjust or control the suspensioncharacteristics.

Air may be entered or exhausted via pilot operated check valves 171 and172, which require a minimum pilot pressure to activate the valve andallow pressure to be removed or added through the valve. Valve 171connects the back pressure 152 of the air spring 150 to the gas supplyvehicle control system 50 and the air supply 70. Valve 172 connects theactuator pressure 151 to the gas supply vehicle control system 50 andthe air supply 70. The valves 171 and 172 require pilot pressure tooperate as a fail safe to avoid unwanted loss of pressure in case of airsupply failure. Without pilot pressure, the suspension unit 30 and thespring 150 are isolated from the vehicle and the air supply 70 such thatno leakage into or out of the suspension unit 30 is possible (fail safemode). This technique protects the suspension unit 30 and/or the vehicleair system shown in FIG. 1 from being drained down if a major leakoccurs. It is contemplated that the air pressure in the spring 150 canbe supplemented or reduced at any time but more preferably when thevehicle is stationary or moving slowly.

Air may be fed through the valves 171 and 172, through a slip ring, anddown passages in the spring piston shaft 154. The passages in the piston154 may directly connect to opposite sides of the cylinder 153, theactuator pressure 151 and the back pressure 152. This double acting aircylinder approach allows the spring's characteristics to be tuned to getthe best spring rate characteristics for a given circumstance. Typicalpressures may be 1000 psi in the actuator pressure 151 and 400 psi inthe back pressure 152. Increasing actuator pressure 151 will cause theunit to push harder on the ground, thus helping to raise the vehicle.Increasing back pressure 152 will make the suspension feel stiffer andbe less inclined to lean during a turning maneuver. It is contemplatedthat the back pressure 152 is typically set once and left until amaintenance check. However, it can be adjusted any time.

In FIG. 5, the double acting, non-linear pneumatic suspension's uniquerebound roll-off traits are shown and compared to a single acting unitand to a typical linear (metal) spring. The graph displays thedisplacement of the suspension unit 30 on the horizontal axis andforce-lbs exerted by the suspension unit 30 against the ground on thevertical axis. The line A represents the single acting spring unit withno back pressure 152. The three different lines B, C, and D on the graphrepresent the spring characteristics of a dual-acting cylinder springwith different levels of back pressure 152, with line B having the leastamount of back pressure 152 and line D having the greatest amount ofback pressure 152. Finally, line E represents a typical linear spring.

When the suspension unit 30 is subjected to a vertical load, such as abump during operation, the suspension unit 30 is displaced in thepositive direction and the gas exerting the actuator pressure 151 iscompressed. This positive displacement is known in the art as the jouncecondition. As shown, the force-lbs exerted on the suspension unit 30 bythe spring 150 dramatically increase with the positive rise in thedisplacement for each line A–D.

In the negative displacement or rebound condition, the lines separate asthe gas exerting the back pressure 152 is compressed. Lines B, C, and Dapproach zero force-lbs due to the back pressure 152 resisting therebound condition. The spring with the greatest back pressure 152, theline D, approaches zero first, the back pressure 152 canceling the forceon the suspension unit 30 from the actuator pressure 151. The line Bcrosses zero at about 6 inches of negative displacement or rebound. Itshould be noted that the dual acting springs approximate the linearspring by falling off to zero force-lbs near the maximum rebound travelof the suspension unit 30.

However, without back pressure 152 to push against the actuator pressure151 in the rebound condition, the single acting spring and line A do notapproach zero within the range shown in the FIG. 5. Therefore, thespring characteristic of line A does not approximate the characteristicsof a linear spring suspension at full extension in the rebounddirection.

Therefore, the dual-acting springs are shown to have essentially asoft-hard nature in jounce as shown by the non-linear increase inforce-lbs as the suspension unit reaches full extension in positivedisplacement. Unlike the single acting spring, the dual-acting springemulates the linear spring in rebound by approaching zero at the fullextension in negative displacement. It is contemplated that the actuatorpressure 151 may be 1000 psi and the back pressure 152 may be 400 psifor the spring characteristics shown by line B.

The spring 150 and the back pressure 152 features may also includeanother important benefit. By increasing the back pressure 152, thesuspension unit 30 may be retracted or raised. Thus, the back pressure152 may be increased enough to raise a wheel attached to the suspensionunit 30 off the ground such that the wheel may be removed to change atire or perform maintenance on a single suspension unit 30 withoutraising the entire vehicle. Variable control of the back pressure 152may also function to as raising/lowering mechanism for a vehicle's noseby controlling the back pressure 152 in multiple suspension units 30 ina vehicle. This variable control may be employed for uses such asattitude adjustment or control of a dozing blade.

It is contemplated that a rotary potentiometer may be positioned on thecenterline of the pivoting axis of the rotatable connection 120,rotatable connection 170 or other rotating joints where the rotation ofthe suspension unit 30 may be measured. The rotary potentiometer maysense unit angle, which can be fed to the height control system tomanage air flowing to or from the spring 150 by keeping track of thesuspension unit 30 angle or displacement. It is also contemplated thatload changes or temperature effects may be monitored via the rotarypotentiometer and/or actuator air pressure. This load information, fromthe suspension units 30 on a vehicle, may be used by the height controlsystem 50 to channel air into or out of the actuator pressure 151 and/orthe back pressure 152 of the spring 150 when the spring 150 is not atits assigned angle.

FIG. 6 shows a perspective view of a ring bearing of the suspensionsystem according to one aspect of the invention. The bearing 200includes a mounting plate side 220 and a trailing arm side 210. Thebearing may also include a hollow center 230 for the passage of supplylines 300 or mechanical gears (not shown) through to the hollow centerof the trailing arm 100. The bearing 200 also includes external threads240 for detachably connecting the bearing 200 to the trailing arm 100and external threads 250 for detachably connecting the bearing 200 tothe mounting plate 110. It is contemplated that the hollow center 230may include a 5.5 inch diameter hole through the bearing 200. The hollowcenter 230 is large enough to allow several power cables and coolantlines to be fed through the bearing 200 and the hollow trailing arm 100to the wheel mount 130. The hollow center 230 may also large enough toallow a drive shaft to fit though for applications requiring gearsinstead of electrical power.

External threads 250 remove the need for a flange attachment of thebearing 200 to the mounting plate 110 or the trailing arm 100. Althoughthe embodiments described herein include the use of external threads toattach the bearing 200 to the mounting plate 110 and the trailing arm100, the bearing 200 may also be attached to the mounting plate 110 andthe trailing arm 100 in other ways without deviating from the scope andspirit of the invention.

It should be noted that the use of the external threads 240 and 250 onthe bearing 200 allows the size of the center opening 230 to bemaximized. Consequently the amount and size of supply lines 300, asshown in FIG. 8, may allow the transmission of adequate power andnecessary fluids, for an electrical drive motor in the wheel assembly10, through the bearing 200 without the use of slip rings for the powerand fluids. Likewise, the size of the center opening 230 also allows formore efficient and reliable mechanical transmission through the bearing200 and through the trailing arm 100, by providing sufficient space forenlarged drive shafts and gears.

In FIG. 7, another view of the suspension system according to one aspectof the invention is shown and the unit 30 is shown in a static position,jounce position, and rebound position. It should be noted that thevertical travel of wheel mount 130 is a function of the geometry of thesuspension unit 30 and the distance between the rotatable connection 120and the wheel mount 130. The amount of rotation of the trailing arm 100may also be a function of the spatial relationship between the trailingarm 100 and the spring 150 and the damper 170. It is contemplated thatthe vertical travel in the jounce position to be approximately 13 incheswith about 39.3 degrees of rotation above the horizontal. Further, thevertical travel in the rebound position may be approximately 6 incheswith about 39.3 degrees of rotation below the horizontal. It should benoted that the static position of the trailing arm may rest at an angleof 13.5 degrees below the horizontal with the wheel hub 130 restingapproximately 3.5 inches below the rotatable connection 120.

It is also contemplated that the range of vertical travel of the wheelmount 130 may be passively controlled with the spring 150 and the damper160 and the geometry of the connections between the trailing arm 100,the spring 150, the damper 160, the connection 120 and the connection170. However, it is also contemplated that the vertical travel may beactively controlled by dynamically adjusting the air pressure of theactuator pressure 151 and the back pressure 152 and active actuators inthe damper 160.

In FIG. 8, a partial cut-away view of the suspension system according toone aspect of the invention is shown. It is contemplated that thetrailing arm 100 may be hollow and carry within its structure supplylines 300 or mechanical gears (not shown in the drawings) from therotatable connection 120 to the wheel mount 130. For use with anelectrical drive within the hub of a wheel assembly 10, the supply lines300, as shown in FIG. 3, pass through the hull, through the mountingplate 110, through a hollow bearing 200, and into the trailing arm 100.The supply lines 300 may include the supply lines indicated in FIG. 1.However, the number of supply lines 300 may be more or less than thoseshown in either FIG. 1 or FIG. 8. Further, the supply lines 300 mayprovide different types and numbers and different shapes and crosssections, including flat supply lines, in order to permit the trailingarm 100 to rotate about the connection 120 without deviating from thescope and spirit of the invention.

The supply lines 300 may be flexible and pass through the hollowtrailing arm 100 to the wheel mount 130. The wheel mount 130 is shown astransparent in FIG. 8 such that the connections of the supply lines 300to the wheel mount or hub 130 may be seen. The supply lines 300 mayinclude a set of pins and connectors/disconnectors arranged around thewheel spindle 140 to allow direct plug in of a wheel assembly 10 with noleakage of fluids. It is contemplated that the set of pins andconnectors will directly connect to matching connectors in the wheelassembly 10 and the electrical drive or electrical motor within the hubof the wheel assembly 10. The pins and disconnects may include differenttypes and shapes of connectors for different types and numbers of supplylines 300. FIG. 8 also shows three possible types of self-sealingplug-in connectors 310, 320, and 330 of different sized for providingelectrical and other fluids and supplies to the wheel assembly 10.

In FIG. 9, a bottom view with a partial cut-away of the suspensionsystem according to one aspect of the invention is shown. The trailingarm 100 and the bearing 200 are partially removed exposing theattachment of the trailing arm 100 to the bearing 200 and the hollowcenter 230. As seen in the FIG. 9, the connection of the mounting plate110 to the bearing 200 does not require flanges or other mountingstructures. As such, the overall diameter of the rotatable connection120 may be effectively controlled while permitting the diameter of thehollow center 230 of the bearing 200 to be enlarged as much as possible.The hollow center 230 may therefore accommodate both electrical andmechanical power transfer through the hollow section 101 of the trailingarm 100 to the wheel mount 130 as illustrated in FIG. 8.

In FIG. 10, a side view with a partial cut-away of the suspension systemaccording to one aspect of the invention is shown. The mounting plate110 may be mounted flush against a hull of a vehicle 500. The hull 500may also include holes for the passage of parts of the mounting plate110 and for the passage of mechanical or electrical power components forpowering the wheel assembly 10. The rotatable connections 120 and 170may be dimensionally spaced as shown in FIG. 10 as part of thesuspension unit 30 geometry. The bearing 200 is shown in further detailattached to the trailing arm 100 by the external threads 240 of thebearing 200. The bearing 200 is also shown attached to the mountingplate 110 by the external threads 250 of the bearing 200. A dirt seal112 may also be seen in FIG. 10 to keep dirt and debris out of theinterior of the rotatable connection 120 and the hollow section 101 ofthe trailing arm 100.

It is contemplated that the diameter of the bearing 200 may be enlargedor reduced in order to accommodate different designs and performancerequirements without deviating from the scope and spirit of theinvention. It should be noted that the width of the suspension unit 30from the outside edge of the hull 500 to the outside surface of thetrailing arm 100 shown in FIG. 10 may be reduced to 4 inches. This maybe accomplished because of the reduced profile of the externallythreaded bearing 200 allowing additional space to be utilized by thehull or the wheel assembly 10. The width of the trailing arm 100 mayalso be expanded and the size of the bearing 200 enlarged to accommodateadditional electrical or mechanical power transmission to the wheelmount 130. A typical clearance between the hull 500 and a wheel assembly10 may required no more than 6 inches including accommodations forchains on the tires during difficult weather conditions.

FIG. 11 illustrates an exploded view of the suspension unit 30. The hull500 may include holes 501 and 502. Hole 501 may be aligned with themultiport assembly or the connection 170 and may provide an opening forpressurized air from the gas supply vehicle control system 50 to besupplied to the valves 171 and 172 and the spring 150. The hole 502 maybe aligned with the connection 120 and may provide an opening for supplylines 300 as shown in FIG. 8. The supply lines 300 may pass through themounting plate 110, a bearing seal 260, the bearing 200, and into thehollow section 101 of the trailing arm 100. It should be noted that theonly element of the suspension unit 30 that may not be applied to eitherthe right or left hand side of a vehicle is the trailing arm 100. Assuch, the design of the suspension unit 30 may be simplified and costeffective by reducing fabrication and design costs of parts that may bemounted on either side of the hull 500.

It should be noted that the supply lines 300, as shown in FIG. 8,originating from the opposite side of the hull 500 from the suspensionunit 30, pass through the opening 502 in the hull 500. The supply linesthen pass through the suspension mounting plate 110, the bearing seal260, the ring bearing 200 and finally into the passage 101 of thetrailing arm 100. Although a slip ring may be used to pass the supplylines 300 through the bearing 200 and into the trailing arm 100, it isimportant to note that no slip ring is required as shown in FIG. 11 topass the supply lines 300 from the hull 500 to the wheel mount 130.

1. A trailing arm suspension system to be interfaced between a hull of avehicle and a wheel of the vehicle, the suspension system comprising: anarm element having a first end and a second end, the arm elementincluding a passage therein; a wheel mount positioned between the firstend and the second end of the arm element and connected to the passageof the arm element; a spring element having a first end and a secondend, the second end of the spring element being attached to the secondend of the arm element; a damper element having a first end and a secondend, the second end of the damper element is being attached to thesecond end of the arm element; a ring bearing including a first set ofexternal threads, the first set of external threads being structured andarranged to secure the ring bearing to the arm element; and a mounting,the first end of the arm element and the mounting being rotationallyconnected by the ring bearing; wherein the spring element and the damperelement are positioned external to and above the arm element.
 2. Thesuspension system according to claim 1, wherein the ring bearing furthercomprises a second set of external threads, the second set of externalthreads are structured and arranged to secure the ring bearing to themounting plate.
 3. The suspension system according to claim 1, whereinthe mounting plate is symmetrical about at least one axis.
 4. Thesuspension system according to claim 1, wherein the ring bearing and thewheel mount are connected by a mechanical transmission passing throughthe ring bearing and the arm element.
 5. The suspension system accordingto claim 1, wherein the spring element includes a gas piston cylinder.6. The suspension system according to claim 5, wherein the gas pistoncylinder includes a dual-acting air cylinder with air independentlysupplied to both sides of the gas cylinder piston.
 7. The suspensionsystem according to claim 1, wherein the damper element is positionedabove and substantially parallel to the spring element.
 8. A trailingarm suspension system to be interfaced between a hull of a vehicle and awheel of the vehicle, the suspension system comprising: an arm elementhaving a first end and a second end, the arm element including a passagetherein; a wheel mount positioned between the first end and the secondend of the arm element and connected to the passage of the arm element;a spring element having a first end and a second end, the second end ofthe spring element being attached to the second end of the arm element,the spring element positioned external to and above the arm element; adamper element having a first end and a second end, the second end ofthe damper element being attached to the second end of the arm element,the damper element positioned external to and above the arm element; abearing coupled to the arm element; and a plurality of supply linespassing through the ring bearing and the passage of the arm element. 9.The suspension system according to claim 8, further comprising a wheelassembly mounted to the wheel mount and a plurality of connectorsconnecting the plurality of supply lines to the wheel assembly.
 10. Thesuspension system according to claim 9, wherein the wheel mount furthercomprises a spindle and wherein the plurality of connectors arestructured and arranged about the spindle.
 11. The suspension systemaccording to claim 9, wherein the wheel assembly includes an electricdrive motor.
 12. A suspension system to be interfaced between a hull ofa vehicle and a wheel of the vehicle, the suspension system comprising:an arm element having a first end and a second end; a wheel mountpositioned between the first end and the second end of the arm element,the wheel mount and the first end of the arm element coupled by apassage in the arm element; a spring element having a first end and asecond end, the second end of the spring element is attached to thesecond end of the arm element, the spring element positioned external toand above the arm element; a damper element having a first end and asecond end, the second end of the damper element is attached to thesecond end of the arm element, the damper element positioned external toand above the arm element; and an electric drive motor coupled on thewheel mount.